add error handling for close() call

[ust.git] / libust / tracectl.c

diff --git a/libust/tracectl.c b/libust/tracectl.c
index 3cb86edc80180f535e8a5773d8413ee11032db64..e40a905d5f6bb5b6fa6e4909005e65acb5c55d00 100644 (file)
--- a/libust/tracectl.c
+++ b/libust/tracectl.c
@@ -17,6 +17,7 @@
 
 #define _GNU_SOURCE
 #include <stdio.h>
+#include <stdlib.h>
 #include <stdint.h>
 #include <signal.h>
 #include <sys/types.h>
@@ -26,8 +27,7 @@
 #include <fcntl.h>
 #include <poll.h>
 #include <regex.h>
-
-#include <urcu-bp.h>
+#include <urcu/uatomic_arch.h>
 
 #include <ust/marker.h>
 #include <ust/tracectl.h>
@@ -125,15 +125,6 @@ static void print_markers(FILE *fp)
 
 static int init_socket(void);
 
-/* This needs to be called whenever a new thread is created. It notifies
- * liburcu of the new thread.
- */
-
-void ust_register_thread(void)
-{
-       rcu_register_thread();
-}
-
 int fd_notif = -1;
 void notif_cb(void)
 {
@@ -241,9 +232,13 @@ void process_blocked_consumers(void)
                                continue;
                        }
                        if(result == 0) {
+                               int res;
                                DBG("PRODUCER END");
 
-                               close(bc->fd_producer);
+                               res = close(bc->fd_producer);
+                               if(res == -1) {
+                                       PERROR("close");
+                               }
 
                                list_del(&bc->list);
 
@@ -357,10 +352,7 @@ static int do_cmd_get_shmid(const char *recvbuf, struct ustcomm_source *src)
                }
        }
 
-       if(found) {
-               buffers_to_export--;
-       }
-       else {
+       if(!found) {
                ERR("channel not found (%s)", channel_and_cpu);
        }
 
@@ -695,6 +687,14 @@ static int do_cmd_get_subbuffer(const char *recvbuf, struct ustcomm_source *src)
 
                        list_add(&bc->list, &blocked_consumers);
 
+                       /* Being here is the proof the daemon has mapped the buffer in its
+                        * memory. We may now decrement buffers_to_export.
+                        */
+                       if(uatomic_read(&buf->consumed) == 0) {
+                               DBG("decrementing buffers_to_export");
+                               buffers_to_export--;
+                       }
+
                        break;
                }
        }
@@ -823,8 +823,6 @@ void *listener_main(void *p)
 {
        int result;
 
-       ust_register_thread();
-
        DBG("LISTENER");
 
        for(;;) {
@@ -964,7 +962,7 @@ void *listener_main(void *p)
 
                        DBG("trace destroy");
 
-                       result = ltt_trace_destroy(trace_name);
+                       result = ltt_trace_destroy(trace_name, 0);
                        if(result < 0) {
                                ERR("ltt_trace_destroy failed");
                                return (void *)1;
@@ -1186,16 +1184,8 @@ static void __attribute__((constructor)) init()
         */
        pidunique = make_pidunique();
 
-       /* Initialize RCU in case the constructor order is not good. */
-       rcu_init();
-
-       /* It is important to do this before events start to be generated. */
-       ust_register_thread();
-
        DBG("Tracectl constructor");
 
-       /* Must create socket before signal handler to prevent races.
-         */
        result = init_socket();
        if(result == -1) {
                ERR("init_socket error");
@@ -1348,7 +1338,7 @@ static void destroy_traces(void)
                ERR("ltt_trace_stop error");
        }
 
-       result = ltt_trace_destroy("auto");
+       result = ltt_trace_destroy("auto", 0);
        if(result == -1) {
                ERR("ltt_trace_destroy error");
        }
@@ -1425,7 +1415,7 @@ static void __attribute__((destructor)) keepalive()
 
        destroy_traces();
 
-       ustcomm_fini_app(&ustcomm_app);
+       ustcomm_fini_app(&ustcomm_app, 0);
 }
 
 void ust_potential_exec(void)
@@ -1453,9 +1443,14 @@ static void ust_fork(void)
        struct blocked_consumer *deletable_bc = NULL;
        int result;
 
+       /* FIXME: technically, the locks could have been taken before the fork */
        DBG("ust: forking");
+
+       /* break lock if necessary */
+       ltt_unlock_traces();
+
        ltt_trace_stop("auto");
-       ltt_trace_destroy("auto");
+       ltt_trace_destroy("auto", 1);
        /* Delete all active connections */
        ustcomm_close_all_connections(&ustcomm_app.server);
 
@@ -1468,9 +1463,13 @@ static void ust_fork(void)
                list_del(&bc->list);
        }
 
+       /* free app, keeping socket file */
+       ustcomm_fini_app(&ustcomm_app, 1);
+
+       buffers_to_export = 0;
        have_listener = 0;
-       create_listener();
        init_socket();
+       create_listener();
        ltt_trace_setup("auto");
        result = ltt_trace_set_type("auto", "ustrelay");
        if(result < 0) {